1. Field of the Invention
This invention relates to a support pole and more particularly to a means for providing a mechanical connection of the shaft of the support pole to a baseplate with that connection providing a unique breakaway solution.
2. Description of the Related Art
Support poles for supporting lights, etc., thereon are commonly constructed of a composite material or a metal material such as aluminum or steel. In most instances, the support pole comprises a pole member or shaft which is secured to a flat baseplate which in turn is secured to a concrete footing. When the shaft is comprised of aluminum or steel, the shaft is normally welded to the metal baseplate. If the shaft is constructed of aluminum, the welding operation may weaken the shaft in the area of the weldment. Further, the welding operation adds to the overall cost of the support pole. When the shaft is comprised of a composite material, such as graphite fibers, carbon fibers, etc., it is usually necessary to form the baseplate with the shaft, which increases the cost of manufacturing or fabricating the same. Further, in all instances, whether the shaft is comprised of metal or composite materials, the breakaway characteristics of the shaft with respect to the baseplate must be considered.
A support pole is described which includes a horizontally disposed baseplate for attachment to a footing with the baseplate having an upper surface and a lower surface. The baseplate has an opening formed therein which extends between the upper surface and the lower surface and which is adapted to have the lower end of the hollow pole member or shaft received therein. The shaft is shaped at its lower end to create a deformation to provide a mechanical connection of the shaft to the baseplate. In one form of the invention, the deformation enlarges the diameter of the shaft. In another embodiment, the deformation may reduce the diameter of the shaft. In yet another embodiment, two deformations are created in the shaft, one above and one below the baseplate. In yet another embodiment of the invention, a single deformation is created in the shaft, with the deformation being located within the baseplate. The deformation(s) may extend completely around the shaft perimeter or in a selected area or areas. The deformation profile affects the load capacity, fatigue and breakaway performance of the support pole. The baseplate profile also affects the load capacity, fatigue and breakaway performance of the support pole. The opening in the baseplate which receives the shaft may be shaped to provide torsional resistance and may have material added for fatigue or abrasion issues. The baseplate to shaft connection described herein eliminates welding, post heat treatment and enables the weight of the support pole to be reduced.
It is therefore a principal object of the invention to provide an improved support pole.
Still another object of the invention is to provide a mechanical connection for the shaft of the pole to a baseplate.
Still another object of the invention is to provide a baseplate to shaft connection which provides a unique breakaway solution.
Still another object of the invention is to provide a support pole having a deformation provided on the shaft thereof for accommodating a baseplate.
Still another object of the invention is to provide a support pole wherein a deformation enlarges the diameter of the shaft.
Still another object of the invention is to provide a support pole wherein a deformation reduces the diameter of the shaft.
Still another object of the invention is to provide a support pole having a pair of spaced-apart deformations formed in the shaft thereof with one of the deformations being positioned above the baseplate and the other deformation being positioned below the baseplate.
Still another object of the invention is to provide a support pole having a deformation formed in the shaft thereof which is located within the baseplate.
Still another object of the invention is to provide a support pole having a deformation formed in the lower end of the shaft thereof which may extend continuously around the shaft perimeter or which may be provided in selected areas of the shaft perimeter.
Still another object of the invention is to provide a baseplate to shaft connection for a pole member wherein the baseplate opening is shaped to provide torsional resistance.
Still another object of the invention is to provide a baseplate to shaft connection for a support pole wherein the baseplate opening has material added therein for fatigue or abrasion issues.
Still another object of the invention is to provide a baseplate to shaft connection for a support pole wherein the baseplate opening has material added therein for strengthening purposes.
Still another object of the invention is to provide a baseplate to shaft connection for a support pole which may be comprised of metal or composite material.
Yet another object of the invention is to provide a baseplate to shaft connection for a support pole wherein the need for welding the support pole to a baseplate is eliminated.
Still another object of the invention is to provide a baseplate to shaft connection for a support pole which eliminates the need for post heat treatment.
Yet another object of the invention is to provide a baseplate to shaft connection for support pole which results in a weight reduction of the support pole and baseplate.
These and other objects will be apparent to those skilled in the art.